Clamshell bucket unloader with rope operated trolley

ABSTRACT

A boom extending horizontally away from a tower supports a trolley that can be moved along the boom and that supports a turntable, below which there is a clamshell bucket supported by means attached to the turntable. Operating means, supported by the tower, control rope means extending from the tower out around the turntable in order to turn it and the bucket suspended from it.

United States Patent [191 Dykeman Dec. 18, 1973 CLAMSHELL BUCKET UNLOADER WITH ROPE OPERATED TROLLEY [75] Inventor: Howard E. Dykeman, Pittsburgh,

[73] Assignee: Heyl Patterson, Inc., Pittsburgh,

221 Filed: Nov. 15, 1972 211 Appl. No.: 306,919

[52] [1.8. Cl. 212/81, 212/88 [51] Int. Cl. B66c 11/16 [58] Field of Search 212/24, 26, 27, 46 R,

212/63,l3,l4,15, 71, 76, 77, 78, 79, 80, 81, 83, 84, 87,144, 88; 214/14, 15 R, 15 C [56] References Cited UNITED STATES PATENTS 2,896,795 7/1959 Kersting 212/81 FOREIGN PATENTS OR APPLICATIONS 6,516,867 6/1967 Netherlands 212/81 Primary ExaminerEvon C. Blunk Assistant Examiner.lames L. Rowland Art0rneyBrown, Murray, Flick & Peckham [57] ABSTRACT A boom extending horizontally away from a tower supports a trolley that can be moved along the boom and that supports a turntable, below which there is a clamshell bucket supported by means attached to the turntable. Operating means, supported by the tower, control rope means extending from the tower out around the turntable in order to turn it and the bucket suspended from it.

8 Claims, 3 Drawing Figures PATEN'IED DEC 18 I915 SHEET 3 BF 3 CLAMSHELL BUCKET UNLOADER WITH ROPE OPERATED TROLLEY Unloading cranes provided with bucket-supporting trolleys that travel along booms projecting laterally from towers are well known. The clamshell buckets can be raised and lowered and opened and closed. It often is desirable to rotate such a bucket on a vertical axis for less than 180. In the past this generally has been accomplished by an electric motor mounted on the trolley and connected by an electric cable to a control station on the tower. An electric cable extending between the tower and the motor, and the location of the motor on the trolley, have been undesirable features of such cranes.

It is among the objects of this invention to provide a clamshell bucket unloader in which the motor that controls turning of the bucket is located on the tower.

The preferred embodiment of the invention is illustrated in the accompanying drawings, in which FIG. 1 is a side view;

FIG. 2 is an enlarged fragmentary side view of the main trolley; and

FIG. 3 is a diagrammatic perspective view showing how the various flexible lines are strung and operated.

Referring to FIG. 1 of thedrawings, extending substantially horizontally away from one side of the upper portion of a structural steel'tower 1 is a long boom 2. The bottom of the boom is provided with parallel rails 3 for the wheels 4 of a trolley 5, so that the trolley can move back and forth alongv the boom. Inside the trolley a pair of vertical sheaves are rotatably mounted side by side. One of these sheaves supports a line or wire rope 7 that extends down through the bottom of the trolley and around a vertical sheave 8 journalled in the upper part of a bucket 9 of the clamshell or grab-type. The rope then extends upwardly again and is anchored in a manner to be described presently. The other end of the rope is attached to an electrically driven drum 1 l rotatably mounted on the tower for raising and lowering the bucket. The other sheave in the trolley supports a rope 12 that extends down around another set of sheaves 13 in the bucket and then upwardly again to an anchor point that will be explained. The opposite end of this rope is attached to an electrically driven drum l4 rotatably supported by the tower for opening and closing the bucket.

It is a feature of this invention that the bucket can be turned on a vertical axis by an electric motor mounted on the tower instead of on the trolley. Accordingly, a large annular turntable 16 is rotatably supported by the lower portion of the trolley. This lower portion, as shown in FIG. 2, is provided with a circular peripheral recess 17, in which vertical wheels 18 are disposed. These wheels are journalled in bearings 19 attached to the bottom of the turntable so that it is supported by the wheels and can rotate on its axis. The ropes 7 and 12 extend from the two vertical sheaves 6 within the trolley down through a passage through the central area of the lower portion of the trolley and therefore through the encircling turntable, and the adjacent ends of the ropes are secured to anchor members 20 fastened to the bottom of the turntable. Consequently, if the turntable is rotated, the two ropes 7 and 12 that are suspended from it will cause the bucket to turn with it.

To turn the turntable, rope means are provided. Preferaby, this consists of a single rope or line 22 that is doubled upon itself with its end portions wrapped in opposite directions most of the way around the tumtable, to which the ends of the line are secured. From the turntable the laterally spaced lengths of this line extend toward the tower and up around a pair of sheaves 23 supported by the trolley and then over another pair of sheaves 24 also supported by the trolley. From sheaves 24 the lines extend back toward the tower and are eventually wrapped around a rotatable drum 25 supported by the tower and driven by an electric motor 26 (FIG. 1). Consequently, when this drum is rotated, one side of ine 22 will be pulled and the other side will be paid out. This will cause the turntable to turn in one direction or the other and thereby rotate the bucket. The electric motor, being mounted on the tower, is readily accessible. The use of an electric cable between the tower and trolley is avoided.

In order to move the trolley toward the tower and keep all of the lines taut while doing so, there is an auxiliary trolley 28 that runs on a track 29 extending from the inner end of the boom across the tower and out of its opposite side. As shown in FIG. 3, this auxiliary trol ley carries near one end four vertical sheaves 30, 31 and 32. Rope 7 that supports the bucket extends back around sheave 30, while the bucket-closing rope l2 extends around sheave 31. The two lengths of the bucketrotating rope 22 extend around the two end sheaves 32. All of these ropes then extend forward and up around another set of four sheaves 33 rotatably mounted in the tower. From this last set of sheaves the ropes extend to their respective drums. It will be seen that if the auxiliary trolley is moved toward the outer end of its track 29, rope 22 will pull the main trolley 5 toward the tower and that all of the lines between the two trolleys will be maintained taut.

In order to move the two trolleys in unison in both directions, the opposite ends of a wire rope 35 are connected to the outer end of the main trolley 5, from which the two parts of the rope extend out around a pair of sheaves 36 journalled in the outer end of the boom. From these sheaves the ropes extend back above the boom and tower and are wrapped a few times around an electrically driven drum 37 rotatably mounted on a pedestal 38 extending above the tower. From this drum the ropes continue back and down to a pair of sheaves 39 supported by a projection 40 from the tower, and then the ropes extend back into the tower and around a pair of sheaves 41 carried by the adjacent end of the auxiliary trolley. From these sheaves the ropes extend out along track 29 again and around a horizontal take-up sheave 42 that is supported from the outer end of the track.

When the trolley drum 37 is rotated in one direction the lines that are wrapped around it will pull trolley 5 toward the outer end of boom 2 and at the same time pay out the lines extending from the drum back to sheaves 39 so that the auxiliary trolley can move in the same direction as the main trolley. When the drum is reversed, the same lines will pull the auxiliary trolley toward the outer end of its track 29 while paying out the lines extending forward to sheaves 36. As the auxiliary trolley moves outwardly along its track, the rope 22 connecting it with turntable 16 of the main trolley will pull the main trolley along with it toward the tower. During travel of the trolleys in either direction the ropes 7, 12 and 22 extending along the boom between the two trolleys are maintained under tension.

According to the provisions of the patent statutes, I have explained the principle of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. A crane comprising a tower, a boom supported by the tower and extending substantially horizontally away from it, a trolley supported by the boom, means for moving the trolley along the boom, a horizontal tumtable supported by the trolley, a bucket below the tumtable, bucket-supporting means attached to the tumtable, rope means extending from the tower out around the turntable, and means supported by the tower for moving said rope means longitudinally to turn the turntable in order to rotate the bucket.

2. A crane according to claim 1, in which said bucket-supporting means include a vertical sheave connected to the upper part of the bucket, and a line extending down from the trolley and around said vertical sheave and up to attachment to said turntable.

3. A crane according to claim 2, including a vertical sheave carried by said trolley for supporting said line, the portion of the line between said vertical sheaves extending through said turntable, and means on the tower connected to said line for reeling it in to raise the bucket.

4. A crane according to claim 1, in which said rope means is a single line having laterally spaced lengths extending between the tower and turntable.

5. A crane according to claim 1, in which said rope means is a single line with its opposite end portions wrapped in opposite directions around said turntable,

the ends of said single line being fastened to the tumtable, and said rope-moving means including a rotatable drum around which said single line is wrapped.

6. A crane according to claim 1, in which said trolley moving means includes an auxiliary trolley at the inner end of the boom, a track for the auxiliary trolley extending away from the side of the tower opposite the boom, sheaves carried by the auxiliary trolley, said rope means extending around said last-mentioned sheaves, means for pulling the bucket-supporting trolley away from the tower, and means for pulling the auxiliary trolley toward the outer end of said track to cause said rope means to pull the bucket-supporting trolley toward the tower.

7. A crane according to claim 6, in which said trolleypulling means include lines connected with both trolleys, sheaves supported by the outer ends of said boom and track and around which said trolley-pulling lines extend, and a rotatable drum supported by the tower, the trolley-pulling lines being wrapped in opposite directions around the drum.

8. A crane according to claim 6, in which said trolleypulling means include lines connected with both trolleys, sheaves supported by the outer ends of said boom and track and around which said trolley-pulling lines extend, and a rotatable drum supported by the tower, the trolley-pulling lines being wrapped in opposite directions around the drum, said rope means being a single line with its opposite end portions wrapped in opposite directions around said turntable, the ends of said single line being fastened to the turntable, and said rope-moving means including a rotatable drum around which said single line is wrapped. 

1. A crane comprising a tower, a boom supported by the tower and extending substantially horizontally away from it, a trolley supported by the boom, means for moving the trolley along the boom, a horizontal turntable supported by the trolley, a bucket below the turntable, bucket-supporting means attached to the turntable, rope means extending from the tower out around the turntable, and means supported by the tower for moving said rope means longitudinally to turn the turntable in order to rotate the bucket.
 2. A crane according to claim 1, in which said bucket-supporting means include a vertical sheave connected to the upper part of the bucket, and a line extending down from the trolley and around said vertical sheave and up to attachment to said turntable.
 3. A crane according to claim 2, including a vertical sheave carried by said trolley for supporting said line, the portion of the line between said vertical sheaves extending through said turntable, and means on the tower connected to said line for reeling it in to raise the bucket.
 4. A crane according to claim 1, in which said rope means is a single line having laterally spaced lengths extending between the tower and turntable.
 5. A crane according to claim 1, in which said rope means is a single line with its opposite end portions wrapped in opposite directions around said turntable, the ends of said single line being fastened to the turntable, and said rope-moving means including a rotatable drum around which said single line is wrapped.
 6. A crane according to claim 1, in which said trolley moving means includes an auxiliary trolley at the inner end of the boom, a track for the auxiliary trolley extending away from the side of the tower opposite the boom, sheaves carried by the auxiliary trolley, said rope means extending around said last-mentioned sheaves, means for pulling the bucket-supporting trolley away from the tower, and means for pulling the auxiliary trolley toward the outer end of said track to cause said rope means to pull the bucket-supporting trolley toward the tower.
 7. A crane according to claim 6, in which said trolley-pulling means include lines connected with both trolleys, sheaves supported by the outer ends of said boom and track and around which said trolley-pulling lines extend, and a rotatable drum supported by the tower, the trolley-pulling lines being wrapped in opposite directions around the drum.
 8. A crane according to claim 6, in which said trolley-pulling means include lines connected with both trolleys, sheaves supported by the outer ends of said boom and track and around which said trolley-pulling lines extend, and a rotatable drum supported by the tower, the trolley-pulling lines being wrapped in opposite directions around the drum, said rope means being a single line with its opposite end portions wrapped in opposite directions around said turntable, the ends of said single line being fastened to the turntable, and said rope-moving means including a rotatable drum around which said single line is wrapped. 